MATH/CMSC 456, 1st Examination
Prof. Jonathan Rosenberg
Friday, March 5, 2010
Instructions. Answer each question in your exam booklet. Show all your work. The point value of each
problem is indicated. The exam is worth a total of 100 points. In problems w
MATH/CMSC 456, 1st Examination
Prof. Jonathan Rosenberg
Friday, March 5, 2010
Instructions. Answer each question in your exam booklet. Show all your work. The point value of each
problem is indicated. The exam is worth a total of 100 points. In problems w
MATH/CMSC 456 (Cryptology)
2nd Examination
Prof. Jonathan Rosenberg
Friday, April 23, 2010
Instructions. Answer each question in your exam booklet. Show all your work. The point value of each
problem is indicated. The exam is worth a total of 100 points.
CMSC/MATH 456 (Cryptology)
Final Examination
Prof. Jonathan Rosenberg
Wednesday, May 19, 2010
Instructions. Answer each question in your exam booklet. Show all your work. The point value of each
problem is indicated. The exam is worth a total of 200 point
+/ Weeld QulxlComsefaw \x Kowwmaoro apuw LIN ﬂ: 5
g/leam/(ryptugra phy/exa m/tvzwwe
How manyelements are in the group 2;“? (Note that 403 = 13 - 31.]
v 6— which of the following gives the 3rd root of92 modulo 1877 (Note that187 = 11 - 17.)
V 7‘
Weeki me‘Cmﬂsﬂa w \x KPMTMKAEDFOB
http:/WWW ourseva rgﬂeam/(ryptugraphy/EKam/LVZVUWEE
Week 5 Quiz
o 5110; nts earned (90%|
Back to Week 5
Quiz passed!
V 1 . consider the fouowingalgonthm for lattnrlng an mteger N pmvded as Input (m b
MATH/CMSC 456 (Cryptology)
Final Examination Solution Key
Prof. Jonathan Rosenberg
May, 2010
1. (30 points) A Hill cipher operates on two-letter blocks by the formula
(x, y ) (x, y )
ab
,
cd
where x, y, a, b, c, d Z26 and gcd(ad bc, 26) = 1 (so that the
MATH/CMSC 456 (Cryptology)
2nd Examination
Prof. Jonathan Rosenberg
Friday, April 23, 2010
Instructions. Answer each question in your exam booklet. Show all your work. The point value of each
problem is indicated. The exam is worth a total of 100 points.
MATH/CMSC 456, 1st Examination Solutions
Prof. Jonathan Rosenberg
March, 2010
1. (15 points total) Suppose that via a known-plaintext attack on an afne cipher x ax + b (mod 26),
you know that the letter c in the plaintext encodes as y and the letter d in
MATH/CMSC 456 (Cryptology)
2nd Examination Solutions
Prof. Jonathan Rosenberg
April, 2010
Instructions. Answer each question in your exam booklet. Show all your work. The point value of each
problem is indicated. The exam is worth a total of 100 points. I
CMSC/MATH 456 (Cryptology)
Final Examination
Prof. Jonathan Rosenberg
Wednesday, May 19, 2010
Instructions. Answer each question in your exam booklet. Show all your work. The point value of each
problem is indicated. The exam is worth a total of 200 point
Weeki me‘Comseva w \x memaoroa puma u»: E: s
htt[MEI/WM.(ourseva.otgﬂeaml(ryptugraphy/EKam/tVZVf/weekrirqmz‘ ﬂ
V 7. which of the failowing problems is hard Ifthe RSAassumptmn holds? \n al|the below, N is a
product ofdlstmtt. large primes p and q, and